TLS Event ID 12014

[dave]

We have Exchange 2007 running on 2003 server. I've been getting this error
since day 1 (2 years ago). I never purchased a cert for mail.domain.com.
We have other certificates for our OWA (webmail.domain.com). How can I
easily stop this error from happening without having to buy an additional
cert? Do we need the TLS? Can this be disabled? Any downsides to
disabling the TLS? Thanks all!

mail.domain.com is for our SMTP mail
webmail.domain.com is for our OWA and RPC over HTTPs.

Event Type: Error
Event Source: MSExchangeTransport
Event Category: TransportService
Event ID: 12014
Date: 8/24/2009
Time: 2:28:59 PM
User: N/A
Computer: EXCHANGE
Description:
Microsoft Exchange couldn't find a certificate that contains the domain name
mail.domain.com in the personal store on the local computer. Therefore, it
is unable to support the STARTTLS SMTP verb for the connector Outbound Mail
with a FQDN parameter of mail.domain.com. If the connector's FQDN is not
specified, the computer's FQDN is used. Verify the connector configuration
and the installed certificates to make sure that there is a certificate with
a domain name for that FQDN. If this certificate exists, run
Enable-ExchangeCertificate -Services SMTP to make sure that the Microsoft
Exchange Transport service has access to the certificate key.

[Andy David {MVP}]

http://technet.microsoft.com/en-us/library/bb510128.aspx